<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<div id="id1">
adsdsa
</div>

<script>
document.getElementById('di1');
id1.style.color='red';
id1.style.fontSize='30px';
id1.style.padding='100px';
</script>
</body>
</html>